In some instances, it may be difficult to access large of amounts of data stored in a database for immediate use. For example, a user may query a database for millions of records of data. As a result, the database is put under a heavy load and may be unable to provide the requested records in a timely manner. It may take the database minutes to process the query while the user requesting the data desires the data immediately.
Additionally, relational databases may not scale very well. Thus, they do not provide timely results to frequent queries to large amounts of stored data.